Tumbler lock and method of fitting the same to a predetermined key change



Nov. 6, 1934.

Filed June 29, 1931 2 Sheets-Sheet l /NVE/V T01? gdm-7F07 f. 17550 5r @am ATTORNEY Nov. 6, w34. E. N. JACOB! L979,939

TUMBLER LOCK AND METHOD OF FITTING THE SAME TO A PREDETERMINED KEY CHANGE Filed June 29, 1931 2 sheets-sheet 2 wwf/wo@ EHI/mrd Afl/2750]?! l 5y QZ@ 21 ,Ih

TTORNEV FFlCE TUmLER LOCK AND MIETHD @F FITTING THE SAME 'llO A IPIREIBE'IER-lilw.l D KEY CGE Edward N. Jacobi, Milwaukee, Wis., assigner to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application .lune 29, 1931, Serial No. 547,5ll3

17 Claims. (Cl. ,Z9-M8) This invention relates to certain new and useneously severing the ends of all of the tumblers ful improvements in locks and refers more parof a cylinder; ticularly to cylinder locks having key operable Figure 6 is a section view through Figure 5 on tumblers. the plane of the line 6--6;

Locks of this type have a wide variety of ap- Figure 7 is a cross section View taken through plications, and in certain instances itis often Figure 5 on the plane of the line -JZ; desirable to fit a new lock to a particular key Figure 8 is a cross section view taken through cha-nge to avoid the necessity for additional keys, Figure 5 on theplane of the line 8 8; or to serve as replacements for defective locks. Figure 9 is anl enlarged detail view of one end l l0 With this purpose in mind this invention conof a tumblerafter it has been severed; t@ templates as an object the provision of a lock Figure 101s a detail View of one of the cutters which is so constructed at the time of its manuof the tool; facture as to enable its tumblers to be readily Figure 11 is a detail view of the cutter, said bitted to any desired key change. view being taken on the plane of the line A1111 15 Another object of this invention resides in the in Figure 10; and u i i0 particular method by which the tumblers of the Figure 12 is a perspective view of a locking lock are bitted to iitthe desired key. tumbler of slightly modified construction.

Another object of this invention resides in the Referring now more particularly to the acspecic construction of the tumblers whereby companying drawings in which like numerals destheir ends may be easily and quickly sheared off ignate like parts throughout the several views, 75

without setting up bending stresses in the tumthe numeral 1 represents a lock cylinder of conblers. ventional construction having a key slot 2 ex- And a further object of this invention resides tending longitudinally therethrough, to communiin the provision of a novel tool whereby the ends cate with a, central enlarged tumbler receiving of all of the tumblers of a lock may be simulchamber 3, the side walls of which are grooved 8o taneously sheared oii. to form guides for a plurality of at tumblers 4. With the above and other objects in view which The tumblers are of special construction, best will appear as the description proceeds, -this illustrated in Figures 3 and 4, and have a ceninvention resides in the novel construction, comtral opening or aperture 5 to receive a key 6 3o bination and arrangement of parts substantially adapted to enter the key slot 2. One edge 'l oi 85 as hereinafter described and more particularly the key forms its bit to move the tumblers to dened by the appended claims, it being undertheir proper positions at which their ends are Stood that Sueh Changes in the precise embodiiiush with the outer cylindrical surface of the ment of the hereindisclosed invention may be cylinder, by engaging one edge 8 of their openmade as come within the scope of the claims. ings 5, so that rotation may be imparted to the 90 In the accompanying drawings, one complete cylinder by means of the key. i example of the physical embodiment of this in- Expansive springs 9 confined between shoulvention is illustrated constructed according to ders 10 communicating with the tumbler guiding the best mode so far devised for the practical grooves in the cylinder and lugs 11 extended from application of ,the principles thereof, and in one side of the tumblers, normally yieldably urge 95 which: the tumblers outwardly of the cylinder in one Figure l is a perspective View of a look Cylhdirection, and stop members 12 preferably in der showing the Condition of its tumblelS before the form of wires extending across the tumbler they are bitted to any particular key Change; guiding slots in the path of the tumbler projec- Figure 2 iS a Side elevation of a look Cylinder tions 11, serve to limit the outward movement 10G with a key in place and parts broken away and of the tumblers by the springs. A in section to illustrate the manner in which the Heretgfore it; has been customary to make the ends 0f the tumblers loiol'eot beyond the Cylinder tumblers with their openings 5 located at difwalls prior to being out 01T; ferent distances from their ends to accommodate Figure 3 is a cross section view taken through the dierent portions of a key and by the proper iOi Figure 2 on the plane of the line 3 3; selection of tumblers, as governed by the particu- Figure 4 is a view similar to Figure 2 and lar key change to which the lock was to belong, showing the tumblers cut oir to proper length; the cylinder .was made up to respond to a key Figure 5 is a side view, with parts broken away of said particular key change. But this invenandin section, of a tool designed for simultation contemplates the making of all of the tum- 110 blers alike with their openings 5 substantially at a medial point between their ends and with thelength of the tumblers greater than the diameter of the lock cylinder.

Figure 3 illustrates a tumbler oi this type in position in the lock cylinder and with a key also inserted. It is observed that both ends of the tumbler project beyond the outer surfaces of the cylinder. This is true of all of the tumblers in the cylinder. `With the key in position the projecting ends of the tumblers are then cut off ilush withthe surface of the cylinder and in this manner the lock may be .quickly bitted to any particular key change.

Both ends of the tumblers are severed simultaneously by a single uninterrupted shearing stroke, and for this purpose a tool such as shown in Figure 5 is preferably employed. This tool comprises as its essential elements two complementary cutters 13 mounted for movement toward each other and between which the assembled cylinder is positioned so that as the cutters approach each other they simultaneously shear off both ends of all of the tumblers.

To provide relief for the portions to be sheared o and to reduce the amount of metal to be cut, the ends of the tumblers are bifurcated as at 14. In the particular tumblers illustrated the bifurcated ends are provided by forming V shaped slots in the end portions of the tumblers so that the remaining projections 15 are substantially triangular in shape with their bases innermost. If desired, the V shaped slots may be replaced by any other shaped cut which results in roughly triangular shaped projections.

The cutting away of the central portion of the tumbler ends not only serves to reduce the amount of metal it is necessary to cut, but the particular shape of the projections 15. precludes the possibility of the cutting tools bending the ends of the tumblers and insures a clean cut edge, for the triangular ends of projections 15 are so proportioned as cantilever beams, that the shearing stress at any point at which the cutters might act is less than the bending resistance of the remainder of the beam from the cut point to the point of attachment to the body of the tumbler.

The device for shearing the tumbler ends comprises a pair of cooperating cutters 13 slidably mounted in the arms of a substantially U shaped block or supporting element 16. As best illustrated in Figures 6 and 10 the cutting ends of the the mounting member 16. At the bottom of the cylinder receiving chamber 18 is a plug 19 which is non-rotatably secured in the body of the mounting member and has a recess 20 and a projection 21 to receive a cam 22 and extend into an opening (not shown) in the inner end of the cylinder, respectively, so as to hold the cylinder against rotation in its proper position with respect to the cutters 13.

Obviously this position is one at which the axes of the tumblers are parallel the planes of the cutvting edges 1'7 so that as the cutters 13 are brought together they engage simultaneously all four corners of the tumblers, the cutters being wide enough to encompass all of the tumblers.

The movement of the tumblers toward and away from each other is preferably limited by means of stop pins 23 fixed to the cutters and moving in openings 24 in a cover plate 25 secured to the mounting member and serving to close the slots A26 in the mounting member in which the cutters move.

Expansive springs 27 are also provided to yieldably maintain the cutters in open position. These springs may be conveniently located in recesses 28 formed in the mounting member tc be conilned between the inner ends of the recesses and pins 29 fixed to the cutters.

The cutters 13 may be moved toward each other to sever the tumbler ends in any desired manner,

as by placing the tool in a vice with the outer ends of the cutters engaging the faces of the vice and closing the vice. However it has been found preferable to provide means as part of the tool, for moving the cutters toward each other. This means consists of a yoke member 30 having its medial portion slidably received in a guideway 31 formed in the mounting member, with one of its laterally directed ends 32 engaging directly the outer end of one of the `cutters 13, and the other laterally directed end 32 provided with an internally threaded bore to receive an aportured screw 33 which engages the outer end of the other cutter. rlightening of the screw 33 draws the cutters toward each other.

To preclude the possibility of sharp edges or burrs on the cut ends of the tumblers, the cutting edges 17 may be serrated to provide round bottomed channels 34, as illustrated in Figures 10 and 11, one being provided for each tumbler so that the ends of the tumblers, after being severed assume a shape such as shown in Figure 9. However it is not essential that the cutting edges be formed in this manner.

1f desired, the tumblers may be provided with V shaped grooves 35, see Figure 12, at each side, and extending transversely across the four corners or projections 15 to mark the possible places at which the tumbler may be cut. These grooves would be mere scratches in depth but would relieve` the cutting effort and would assure the tumblers being cut clean and free from burrs, without the necessity for special shaped cutting edges to chamfer the tumblers.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent to those skilled in the art to which an invention of the character described appertains, that I provide a novel lock and method of hitting its tumblers to any desired key change.

What I claim as my invention is:

l. The method of tting a tumbler lock to a given key which comprises, forming the tumblers of the lock of greater length than the diameter of its cylinder, inserting the key intothe lock, and shearing 0E the projecting ends of the tumblers in one uninterrupted stroke.

2. The method of tting a tumbler lock to a desired key which comprises, forming the tumblers of the lock of greater length than the diameter ci its cylinder, moving the tumblers into the positions to which they are moved by the key, and shearing ou the ends of the tumblers projecting from the cylinder in one uninterrupted stroke.

3. 'I'he method of tting a tumbler lock to a desired key which comprises, forming the tumblers of the lock of greater length than the diameter of its cylinder, inserting the desired key in the lock, holding the lock against movement, and shearing oi the projecting ends of the tumblers in one uninterrupted stroke.

4. Ina lock of the character described, a cylinder having a key slot, and key operable tumblers of greater length than the diameter of the cylinder mounted in the cylinder to be actuated by a key inserted into the key slot, said tumblers having their ends cut to form projections narrow at their outer ends and wide at their bases to facilitate shearing off the tumbler ends.

5. A locking tumbler for use with cylinder locks, comprising a i'lat member having a key receiving aperture, a spring engaging projection, and both ends bifurcated.

6. A locking tumbler for use with cylinder locks comprising a fiat piece of metal having av key receiving aperture, and spaced projections narrow at their outer ends and wide at their bases, extended from each end.

'7. A locking tumbler for use with cylinder locks formed of a flat piece of metal with a central key receiving aperture and having both its endsmedially cut to form slots wide at their outer ends and narrow attheir inner ends.

8. A locking tumbler for use in cylinder locks comprising, a at member having a key receiving aperture, and having both its ends medially cut away to form spaced projections wider at their connection with the body of the tumbler than at their outer ends.

9. The method of adapting a tumbler lock to a predetermined key change which comprises, forming all of the tumblers of the lock alike and of greater length than the diameter of its cylinder, inserting a key of the predetermined key change into the lock to move the tumblers` to their proper positions, and shearing off the projecting ends of the tumblers in one uninterrupted stroke.

10. The method of tting a tumbler lock to a desired key change which comprises, forming the tumblers of the lock of greater length than the diameter of its cylinder, inserting the desired key in the lock to move the tumblers to their proper positions, holding the cylinder against movement, and simultaneously applying shearing stress to the opposite edges of the opposite tumblers at both their ends to shear off their projected ends.

11. 'Ihe hereindescribed method of fltting a tumbler lock to a desired key change which comprises, forming the tumblers of the lock of greater` length than the diameter of its cylinder, cutting away the medial portions of the tumbler ends to form projections narrow at their outer ends and Wide at their connection with the bodies of the tumblers, inserting the tumblers in the cylinder of the lock, inserting the desired key in the lock to move the tumblers to their proper positions, and in applying shearing stress simultaneously to the opposite outer edges of the projections at both ends of the tumblers to simultaneously shear o" the projecting ends of the tumblers.

12. 'Ihe method of fitting a tumbler of a cylinder lock to a particular key change which comprises, forming the tumbler with symmetrically disposed projections forming locking corners, inserting the tumbler in its cylinder, holding the tumbler in a predetermined position with respect to the cylinder, and shearing off the projecting corners in one uninterrupted stroke.

13. The method of fitting a tumbler of a cylinder lock to a particular key change which coinprises, forming the tumbler with symmetrically disposed projections providing locking corners, inserting the tumbler in its cylinder, holding the tumbler in a predetermined position with respect to the cylinder, and simultaneously severing all of the projecting corners of the tumbler.

14. A tumbler for cylinder locks of the character described, comprising a flat body portion and a projecting end of such tapered configuration that the shearing stress engendered by a tool acting upon the projecting end to cut off the same is less than the bending stress in the projecting end.

15. The method of fitting a tumbler lock to a given key which comprises forming the tumblers of the lock of greater length than the diameter of its cylinderinserting the key into the lock and simultaneously shearing off the projecting ends of all of the tumblers.

16. The hereindescribed method of fitting a tumbler lock to a given key which comprises forming the tumblers of the lock of greater length than the diameter of its cylinder, holding the tumblers in their predetermined proper positions with respect to the cylinder, and shearing off the projecting ends of the tumblers by an uninterrupted shearing lstroke transverse to the longitudinal axis of the cylinder.

17. The hereindescribed method of fitting a tumbler of a cylinder lock to a particular key vchange which comprises forming the tumbler of a length greater than the diameter of the cylinder, inserting the tumbler in the cylinder, holding the tumbler in a predetermined proper position with respect to the cylinder, and cutting oi the projecting ends of the tumbler by cutting tools simultaneously engaging the opposite sides of the tumbler.

EDWARD N. JACOBI. 

